Retirement Benefits and Trusteed Assets (Net Pension Cost (Credit)) (Details) - Pension plan - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]
Service cost	$ 49	$ 58	$ 57
Interest cost	216	208	214
Expected return on plan assets	(291)	(341)	(352)
Amortization of:
Net actuarial loss	87	59	7
Prior service credit	(1)	(2)	(2)
Settlements	0	0	7
Net pension/other postretirement cost (credit)	$ 60	$ (18)	$ (69)